Rodriguez, who is a 14-time All-Star and played 22 seasons in professional baseball with the Seattle Mariners, Texas Rangers and the New York Yankees, also became the co-owner of the NBA's Minnesota Timberwolves in April 2021.
The 46-year-old, who also owns A-Rod Corp. and already invests in UFC-branded gyms, will now take a seat on the PFL's board of directors. He joined media investment firm Waverley Capital to raise the funding.
The PFL is now reportedly valued at $500 million, an increase of $100million since its $400million estimation in 2021.
PFL will use the investment to sign free agent fighters from other MMA organisations, including UFC.
PFL founder and chairman Donn Davis told CNBC that the PFL wants to build a roster to leverage its pay-per-view "Super Fight" event that's scheduled to debut in 2023.
"They now have a great option - UFC or PFL," Davis said. "We're open for business in the pay-per-view division."
Davis called Rodriguez "innovative in his approach to investing and building companies."
"Alex is building a business career in sports that he wants to equal his baseball career," he said.